Timezone settings?

Hi, I am using freeradius-0.9.3 with postgres 7.4.11. I have the following issue: The radius message from a client has Event-Timestamp displayed as local EDT time, but when Radiusd proccesses the message, the Event-Timestamp was converted to UTC time (as shown in the radacct detail log files). How can I disable this? I checked the timezone setting on the freeradius server machine, and it was set to EDT. Is there a config parameter that tells freeradius not to alter the Event-Timestamp? Thanks, Khoa